Real monarchs were famous for getting their way. They would dispatch armies on a whim, shout “off with their heads” in a fit of pique, and demand dainty dishes like four and twenty blackbirds baked in a pie.

L’état? It was all about them.

Most of today’s monarchs are figureheads, grandfathered by history but checked and balanced by parliaments, councils, a watchful media, and a skeptical public. (For a special report on the state of royalty around the world, go here.) The best royals know they are anachronisms and thus have become astute brand ambassadors. Members of the House of Windsor, for instance, work hard as British boosters and ribbon-cutters. Carl XVI Gustaf of Sweden supports Scouting.

Even Euro-royals more inclined toward fast cars, glittering parties, and yachting can be counted on to back environmentalism and other progressive causes.

Some royals behave badly. Most are poised and dignified. William and Kate, whose imminent marriage has stirred public interest well beyond the British isles, look as if they’ll be the latter – sensible personifications of the generation they come from, able to inspire and charm even indifferent countrymen.

A Briton I know who never let on that she cared for royals once returned from London thrilled at having seen the queen during a parade. “She fairly glowed!” she marveled.

I’ve talked with a few mid-level royals during my days in journalism – Arab crown princes, mostly. By far my most memorable experience of royalty was one quiet morning when I was working as foreign editor of The Boston Globe. The receptionist in the lobby phoned: The King of Uganda was downstairs and would like to meet me.

Actually, he was the Kabaka of Buganda: Ronald Mutebi II, the 37th in a 500-year-old line that reigns in the Ugandan heartland. In the tradition of Central African leaders, he was cruising the city in a small fleet of limousines, dropping in for chats with people he believed were important. Little did he know.

I quickly knotted a tie, borrowed a sport coat, and assembled a few other editors. We exchanged pleasantries with His Highness while sipping beverages from the newspaper’s formal set of Styrofoam. Satisfied, the royal entourage motored off to greet other Beantown eminentos.

Most monarchies that have hung on have earned the respect of their subjects. Start-ups are hard to pull off. From Jordan to Saudi Arabia to Oman, most Middle East royal houses are of recent vintage. Though the longtime rulers of Egypt, Libya, and Yemen were never crowned, all have acted as virtual monarchs. All also attempted to line up sons as successors until recent democracy movements ended their dynastic dreams.

In his withering critique of the monarchy, “Common Sense,” Thomas Paine noted that even if a particular king was covered in glory, that’s no justification for setting up “his own family in perpetual preference to all others for ever.” Besides, Paine said, hereditary succession too often provides “an ass for a lion.”Democracy and rotation in office are the safest path – but I would say that, as an American.

Still, if national pride requires royalty, you can do little better than Queen Elizabeth II, who drove ambulances in World War II and has carried herself with grace through good times and bad.

Who could not have been moved by the parental sadness on her face during a speech at the end of 1992, her “annus horribilis” because of her children’s broken marriages and a devastating fire at Windsor Castle? “We are all part of the same fabric of our national society,” she said. While scrutiny and criticism are natural and healthy, she added, it can be just as effective if done with “gentleness, good humor, and understanding.”

If William and Kate can muster half the dignity and humanity Elizabeth has shown, the Windsor brand will be in good hands.